PainResearch Phase

Endomorphin-2

Overview

Endomorphin-2 is a tetrapeptide (Tyr-Pro-Phe-Phe) that, like endomorphin-1, demonstrates highly selective agonism at mu-opioid receptors. The two endomorphins differ by a single amino acid but share similar receptor selectivity and analgesic properties. Endomorphin-2 is found in spinal and supraspinal sites involved in nociception. Its unique selectivity profile has generated interest in developing analogs that retain efficacy while minimizing respiratory depression and other opioid side effects.

Key Research Findings

Animal studies have confirmed potent analgesic activity of endomorphin-2 in thermal and inflammatory pain models following central administration. As with endomorphin-1, clinical utility is limited by rapid peptidase degradation and poor systemic bioavailability. Medicinal chemistry efforts have produced modified analogs with improved stability, though none have advanced to late-stage clinical trials.

Route of Administration

Endogenous peptide

Regulatory Status

Research Phase

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